Can I Recover 'Recently Deleted' Photos on iPhone?

"I was deleting some pictures in order to free some space on my iPhone 6 Plus but mistakenly deleted some I wasn't supposed to. The problem right now is that I also deleted the pics from the 'Recently Deleted' album. Feel so terrible. How can I recover photos deleted from the recently deleted folder?"

Actually, when a user deletes a photo from the Recently Deleted album, a dialogue would pop out and prompt you "This photo will be deleted. This action cannot the undone." Recently Deleted photos should be carefully treated, especially when you disabled the auto backup/sync on iCloud. Once items removed from the Recently Deleted folder, which usually keeps your recently deleted photos for 30 days, they'll vanish forever with your precious memories.

How to Recover Photos Permanently Deleted from 'Recently Deleted' Folder?